Tomato peeling method



KATSUJI HIRAHARA 3,396,769

TOMATO FEELING METHOD Original Filed April 16, 1965 Aug. 13, 1968 2Sheets-Sheet 1 INVENTOR KATSUJI HIRAHARA M mi-hi! M W ATTORNEY KATSUJIHIRAHARA 3,396,769

TOMATO FEELING METHOD Aug. 13, 1968 Z Sheets-Sheet 2 Original FiledApril 16, 1 965 INVENTOR KATSUJI HIRAHARA /W [a W ATTORNEY United StatesPatent 3,396,769 TOMATO PEELING METHOD Katsuii Hirahara, San Jose,Calif., assignor to FMC Corporation, San Jose, Calif., a corporation ofDelaware Original application Apr. 16, 1965, Ser. No. 448,785, now

Patent No. 3,352,338, dated Nov. 14, 1967. Divided and this applicationApr. 11, 1967, Ser. No. 630,042

3 Claims. (Cl. 146-231) ABSTRACT OF THE DISCLOSURE A method of removingthe softened, caustically treated skins from tomatoes by rolling thetomatoes down an inclined, upwardly moving belt, retarding the movementof the tomatoes down the 'belt, and changing the direction of the pathof the tomatoes as they roll down the belt.

CROSS REFERENCES This application is a division of my copendingapplication Ser. No. 448,785, filed Apr. 16, 1965, now Patent No.3,352,338.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to a method for processing fruit, and more particularly relatesto a method for removing the caustically treated skins from fruit, suchas, tomatoes.

DESCRIPTION OF THE PRIOR ART Fruit, such as tomatoes, have relativelysoft bodies surrounded by relatively thin fragile skins, and must bedelicately handled to avoid damaging the bodies or meat portions of thefruit. Caustically treating the tomatoes leaves the fruit with aloosened skin that is readily removable by contacting or brushingagainst a roughened surface. Normally, regular tomatoes are fruitsubjected to a coring and trimming operation wherein parts of the skinare cut away making further removal of the cut and caustical ly treatedskin easily accomplished.

With the advent of improved, relatively coreless varieties of tomatoes,such as the VF-145 and its hybrid forms, Italian pear-shaped, 131oblongs and other types, it 'became necessary to modify the peelingoperation since the tomatoes were no longer 'acted upon by a coringunit. In other words, since several of the more recent varieties oftomatoes have small cores, if any, the tomatoes leaving the causticsolution are no longer subjected to a coring and cutting operation,making the subsequent peeling of the skins more difficult.

SUMMARY OF THE INVENTION In accordance with the present invention it hasbeen found that lye treated tomatoes can be successfully peeled byincluding the steps of rolling and tumbling the tomatoes down anunsubmerged, firm= upwardly moving friction surface, thereby causingsufficiently rapid relative motion of the tomatoes and the surface tobreak the tomato skin without piercing the skin by the friction surface.In the preferred embodiment of the invention, this relative motion ofthe tomatoes on the friction surface is provided by rolling the tomatoesdown an inclined belt, which moves upwardly contrary to the direction oftomato motion.

The aforesaid rolling action further causes centrifugal flinging of thedislodged skins from the rotating tomatoes.

When a belt is used, as in the preferred embodiment of the invention, ithas been found that by directing a spray of water on the tomatoes asthey roll down the belt, the tomatoes are not only rinsed of their lyetreatment solution, but a thin film of water on the friction sur "iceface of the belt to which the dislodged tomato skins adhere and henceare carried away by the belt.

Another feature of the invention is that the rolling of tomatoes downthe friction surface is intermittently and momentarily impeded bysinuous bafiies so that the tomatoes impinge upon the baifies andrichochet among them for further breaking loose the tomato skins fromthe fruit.

In principle, the tomatoes are rotated and are acted on by a frictionalforce at varying speeds and in varying directions. This force along withthe rotation of the fruit tend to remove the skins from the bodies ofthe tomatoes.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a diagrammatic sideelevation of one processing line of a caustic fruit treating machine onwhich the method maybe employed.

FIGURE 2 is an enlarged diagrammatic longitudinal vertical section ofthe skin eliminating unit shown at the right hand end of the machine ofFIGURE 1.

FIGURE 3 is an enlarged, diagrammatic plan of the skin eliminatingsection of the processing line taken along the lines 3-3 shown in FIGURE2.

FIGURE 4 is an enlarged isometric of a portion of the endless belt shownin FIGURE 3.

FIGURE 5 is a diagrammatic longitudinal section, similar to FIGURE 2 butwith parts broken away, showing a modified form of the skin eliminatingunit.

DESCRIPTION OF THE PREFERRED EMBODIMENT In general, a tomato processingmachine for carrying out the method comprises an elongated frame supportstructure 20 on which is mounted an endless chain conveyor 21 (FIG. 1)having an upper run movable toward the right, as shown in FIGURE 1, tocarry tomatoes T, that are disposed in caps 22, through a series ofprocessing stations. At a loading station 24, a tomato is placed in eachcup. As the tomato is moved to the right, it is carried into a tank 25in which it is treated for a predetermined time with a caustic solution,such as, lye. After leaving the lye tank 25, the tomato is carriedupwardly inside an inclined housing 26 in which excess lye is drainedfrom the tomato and the tomato is exposed to a steam atmosphere for afixed period of time during which the lye on the skin penetrates to thedesired depth to effect loosening of the skin from the flesh of thetomato body. The steam atmosphere in the housing 26 also raises thetemperature of the tomato skin to a predetermined optimum peelingtemperature. After leaving the housing 26, the tomato is carried by thechain conveyor 21 to the skin eliminating section 28 where the skin isremoved from the fruit portion of the tomato. Upon leaving the skineliminating section, the peeled fruit is passed through an immersionsection 30 where it is rinsed and transferred by a conveyor 32 to atrimming station.

With the exception of the skin-eliminating section 28, theabove-mentioned members of the processing line are well known in theart, and a further description thereof may be found by referring toCreed et al., U.S. Patent No. 3,096,800, accordingly, the description isincorporated by reference in the present specification.

The skin eliminating section is best shown in FIGURES 2 and 3 andcomprises an endless belt 36 trained around a horizontal drive roller 38which is keyed on an upper shaft 40. The shaft 40 is journalled forrotation in the frame 20 and in a pair of spaced side plates 41 in awell known manner and has mounted on one end a driven pulley 43 (FIG.3). Each side plate 41 is provided with a protruding bracket 41a. Thebrackets 41a have a plurality of holes 42 spaced along an arc relativeto the shaft 40. To attain a desired inclination of the belt 36,

selected holes in each side plate are aligned with holes in the frame 20and bolts 42a are passed therethrough and securely fastened by nuts in awell known manner. The driven pulley 43 is connected by means of a beltand pulley drive 44 to the rotary shaft of a variable drive electricmotor assembly 46, such as a US. Varidrive Motor sold by US ElectricalMotors, of Los Angeles, Calif. The belt 36 is also trained about ahorizontal idler roller 48 which is keyed on a shaft 50. The shaft 50 isjournalled for rotation in the side plates 41 at a lower elevation thanthe shaft 40 in a manner such that the upper run of the belt 36 travelsupwardly, as indicated by arrow A, in a longitudinal inclined path.Tomatoes being advanced by the conveyor 21 are dropped onto a flat metalchute 52 which is adjustably mounted to the frame 20 above the roller 38by any suitable means. The chute 52 guides the tomatoes onto theupwardly moving upper run of the belt 36. The distance each tomato isdropped from the conveyor 21 to the chute 52 may be varied as desired byadjusting the height of the chute; however, it has been found that adistance of several inches is desirable to partially break the loosenedskin so as to assist in the subsequent peeling operation. In addition,the surface of the chute could be provided with a roughened rubbersurface to increase the breaking of the skin due to the drop.

The belt 36 may be made of any well known flexible synthetic materialwhich is provided with a nibbed, dimpled or otherwise roughened surface36a which retards sliding of the fruit and aids in breaking or crackingthe skin. A typical belt which has proved satisfactory is a Sno-Flake,3-ply belt made of neoprene and manufactured by the Haultain ChampionCo., Inc., of Oakland, Calif. To increase the tumbling action of thetomatoes traveling down the inclined upper run of the belt 36, aplurality of transverse rubber strips 54 (FIG. 4) are vulcanized orotherwise fastened to the outer surface of the belt 36 in a manner so asto impart an additional rotational movement when the strip is carriedupwardly by the belt and strikes the tomato. The belt applies africtional force to the skin of the tomato which tears the skin from thebody of the tomato. The rotational or spinning action of the tomatoresults in a centrifugal force which assists the frictional forceapplied by the belt to the outer surface of the tomato and flings thebroken skin outwardly in sheets away from the main body of the fruit.The skins subsequently mat or adhere to the belt. As a result, the skinsare pulled in a direction opposite to the downward path of travel of thetomato which increases the skin peeling action.

Interrupting or delaying means are provided above the belt 36 and in thepath of the tomatoes rolling down the upper run thereof and, as bestshown in FIGURES 2 and 3, comprise a flexible curtain 60, a set of wavymetal baflles 62 and a plurality of metal pins 64. The curtain, bafllesand pins are all disposed normal to the upper run of the belt 36 and arespaced a distance therefrom such that they do not contact the belt butare still in the path of travel of the fruit tumbling downwardlythereon. The curtain 60 is mounted on a transverse angle bar 61, whichis fastened on the frame 20 by any suitable means, and is made of ahighly flexible material, such as rubber. The curtain 60 serves tomomentarily halt the travel of the tomato which is received from thechute 52. This permits the roughened surface of the belt to act on thetomato and begin its tumbling and tearing action. The curtain 60 isseparated from the belt a distance suflicient to halt the tomato onlytemporarily and, as the tomato passes beneath the curtain, it is rapidlytumbled by the inclination of the upper run of the belt 36 and bycontact with the upwardly moving roughened surface 36a and the rubberstrips 54.

As the tomatoes travel downwardly along the inclined path, they tumbleagainst the undulating baflles 62 which partially impede their downwardtravel. The battles are 4 provided with tabs 62a which are fastened, ina position overlying the belt, to transverse bars 63 by collars 62bformed on the tabs and secured to the bars. The bars 63 are mounted onthe frame 20 by any suitable means. The baflles prevent the tomatoesfrom traveling along a straight path and thus extend the time in whichthey are in contact with the roughened surface of the belt 36. Thebaffles also cause more vigorous contact between the tomatoes and thebelt and thus increase the efficiency of the peeling operation.Furthermore, each time a tomato strikes a baffle the frictional forceapplied to the skin by the belt is in a different direction, since thetomato is deflected across the moving belt rather than merely travelingin one direction with respect to the direction of belt movement. InFIGURE 3 a typical illustration is shown in which a tomato T is shownbeing deflected by a baflie 62 across the belt 36. The direction oftravel of the tomato is indicated by an arrow M whereas the direction ofthe frictional force as applied to the skin of the tomato by the belt isindicated by an arrow F. When the tomato leaves the baflie the directionof the friction force is at an angle with respect to the direction oftomato travel and more effectively removes the tomato skin.

Similarly, the pins 64 which are positioned between the baffles 62,further impede the travel of the tomatoes along the inclined path. Thepins 64 are fastened on the transverse bars 63 as by welding. Thepurpose of the pins 64 is, likewise, to extend the length of time inwhich the roughened surface of the belt may contact the loosened skin ofthe tomato. By the time the tomato reaches the lower end of the belt 36,adjacent the immersing unit 30, substantially all the skin has beenpeeled from the fruit portion of the tomato.

As is best shown in FIGURES 2 and 3, a plurality of nozzles 68 areconnected on a transverse water pipe 70 which is connected to the frame20 in a position overlying the belt, by any suitable means. The pipe 70is connected by a conduit 72 to a source of water under pressure. Thenozzles 68 direct a spray of water on the tomatoes traveling down thebelt, rinsing the peeled tomatoes and applying a thin film of water ontothe surface of the belt 36. As the skins are disengaged from the body ofthe fruit, the peels adhere to the belt and to the thin film of waterand are carried out of the path of the body portion of the tomato.

Positioned beneath the roller 38 and in a position to engage the outersurface of the belt 36 is a flexible resilient scraper 74 which ismounted on the frame 20 above the side wall 76 of a flume 78. The flume78 includes another side wall 80 and :a bottom wall 81 secured to theframe 20. The bottom wall 81 is connected in fluid tight relation to theside walls 76 and 80. The scraper 74 engages the .peelings, which arepartially floating on the thin film of water and carried by the outersurface of the belt 36, and deflects them into the flume 78 where theyare subsequently discharged as by flushing with water. Con sequently,the outer surface of the belt 36 is substantially cleared of peelingsprior to its travel :along the upper run. Since it is imperative thatthe skins of the fruit be contacted by a roughened surface, thisclearing action by the scraper 74 maintains the roughened surface of thebelt eflective for removing the skins from the tomatoes.

The immersion section 30 will now be described and as best shown inFIGURE 2 comprises a tank 82 positioned below the roller 48 and having abottom wall 86, two upstanding side walls 88 (FIG. 3), and twoupstanding end walls 90, only one being shown. The tank is filled withwater from a source, not shown, and serves to rinse the substantiallypeeled tomatoes prior to a further processing step. The tomatoes passingalong the baflles 62 are discharged into the tank 82 at the lower end ofthe belt 36 and are deflected by a plate 92, fastened to one of the endwalls 90, onto the upwardly inclined conveyor 32.

The belt of conveyor 32 is trained about an idler roller 96 that iskeyed on a shaft 97 which is journalled on the frame and about an upperpower-driven drive roller, not shown. A plurality of appendage orshelves 98 are provided on the outer surface of the conveyor 32 inupstanding relation thereto in a manner well known in the art. As thetomatoes are deflected by the plate 92, they are carried upwardly by theappendages on the conveyor 32 and moved to a subsequent handlingsstation, not shown.

In carrying out the method the tomatoes which have been treated in thetank and the inclined portion 26 are carried by the conveyor 21 to theskin eliminating section 28. The tomatoes are dropped from the conveyor21 and strike the chute 52, where an initial breaking of the skinoccurs, and are then deflected onto the upper run of the belt 36. Due tothe inclination of the upper run of the belt 36, the tomatoes begin toslide or tumble down the inclined path until they are engaged by thecurtain 60 and momentarily stopped until the moving roughened surface ofthe belt 36 causes them to begin a pure tumbling action. As the tomatoesleave the curtain 60 they are tumbled along and their paths areobstructed and delayed by the baffles 62 and the pins 64 so that theroughened surface of the belt 36 has sufiicient time to engage theloosened skins of the tomatoes and remove them from the fruit portion.Each time the tomatoes strike a baffle and are deflected in a differentdirection they travel across the moving belt at a different angleresulting in a change in direction between the motion of the tomatoesand the frictional force as applied by the belt. The relative change indirection between the tomatoes and the moving belt causes a morevigorous and rapid peeling action. Also, upon each change of directionthe tomato is slowed, however, since the belt is moving at a constantfast speed the belt further tends to move the skin faster than the bodyof the tomato and thus separate the skin from the tomato.

The inclination of the upper run of the belt 36 and the speed with whichit travels may be varied depending upon the type of fruit being peeled.In one arrangement for the VF-145 variety tomato, the optimum conditionswere an angle of 28 degrees, using an eight foot rolling section for theupper run of the belt 36 and a belt speed of 300 feet per minute. Themore baflles used, the faster the speed of rotation of the belt, and thegreater the angle of inclination of the belt, all are factors whichincrease the amount of contact by the roughened surface of the belt andcauses more vigorous peeling action. Consequently, should the fruitbeing processed have a skin which is not readily removed, the adjustmentof any one, or all, of these three aforementioned features may bechanged to provide a more extensive and vigorous contact. Conversely,when the skin of the fruit is very fragile and easily removable, thebelt angle and speed may be decreased. The above three features; namely,the belt angle of inclination, the belt speed, and the number of bafliesare not critical; however, as aforementioned, there are optimumconditions for each different variety of fruit being peeled.

Upon leaving the belt 36, the peeled tomatoes fall into the immersionunit 30 where any remaining traces of lye or loose bits of peel areremoved. The tomatoes are then carried by the conveyor 32 to anotherstation in the processing line, not shown, where a subsequent operation,such as a final trimming and packing is performed.

A modified form of the belt cleaning portion of the eliminator is shownin FIGURE 5. In this embodiment, the flexible scraper 74 and the flume78 are removed. As a substitute therefor, two additional side walls,only one being shown as at 100, are connected to the end wall 90 of thetank 82. An additional end wall 102 is added connecting the side wallsand a bottom wall 104 in fluid tight relation to form a washing tank 99.The end Walls and 102, the side wall and the other side wall, not shown,

are high enough so as to support a column of water supplied either froma source, not shown, or from the water which spills over the end wall90, such that the lower portion of the roller 48 and the belt 36 areimmersed in the water column. The end wall 102 is slightly lower thanthe end wall 90, and is provided with a spillway 105 which guides theoverflow of water into the flume 106. The flume 106 is substantiallyidentical to the previously described flume 78 of the preferredembodiment. It should suflice to say that the flume 106 also is providedwith a pair of inclined side walls 108 and 110 which are connected by abottom wall 112.. The bottom wall 112 is also fastened to the frame 20at an :angle such that peelings which are washed into the flume over thespillway 105 may be flushed to a disposal area.

The method may also be carried out on the modified embodiment since itoperated identically to the preferred embodiment with the exception thatinstead of the peelings being scraped from the belt by the rubberscraper 74, they are retained on the lower run of the belt 36 and passint-o the column of water supported in the tank 99. As the peelings arecarried into the column of water they are washed from the belt 36 andfloat over the spillway 105 into the flume 106, thus leaving the belt ina substantially cleaned condition as it begins the upper run.

From the foregoing description it will be apparent that the presentmethod provides an effective, inexpensive mode of removing the skinsfrom caustically treated tomatoes and that the method may be employed onvarious other forms of equipment.

It will be understood that the principles of the invention are alsoapplicable for tomatoes which have cores and are first subjected to acoring or cutting operation before being peeled or for tomatoes whichhave cores but are not first subjected to a coring or cutting operation.However, since tomatoes which are first cored are weakened structurally,it is necessary to coordinate the speed, angle and length of the beltfor less vigorous handling than in the case where coreless or uncoredtomatoes are being peeled.

It will be understood that modifications and variations of the inventiondisclosed herein may be made without departing from the scope of thepresent invention.

Having completed a detailed description of the invention so that thoseskilled in the art could practice the same, I claim:

1. The method of removing the skin from lye treated tomato-es or thelike including the steps of rolling the tomatoes down an unsubmerged,firm, upwardly moving friction surface and causing sufliciently rapidrelative motion of the tomatoes and said friction surface to break thetomato skin but without piercing the 'skin by the friction surface andthereby damaging the fruit; and simultaneously causing centrifugalflinging of dislodged skin from the rotating tomatoes.

2. The method of claim 1, including the steps of direct ing a spray ofwater on the tomatoes as they roll down said upwardly moving frictionsurface for rinsing the tomatoes and causing the dislodged skins to:adhere to :a thin film of water on said moving surface, and removingthe skins from the spray zone via said moving surface.

3. The method of claim 1, comprising intermittently and momentarilyimpeding the rolling motion of the tomatoes down said upwardly movingfriction surface for further breaking loose the tomato skins from thefruit.

References Cited UNITED STATES PATENTS 1,394,138 10/1921 Bost et a1.146-233 X 3,017,298 1/1962 Wilson et a1. 146234 3,024,821 3/1962 Bean146--49 W. GRAYDON ABERCROMBIE, Primary Examiner.

